1. Field of the Invention
The present invention relates to a semiconductor device. More particularly, the present invention relates to a photosensitive semiconductor device and manufacturing method thereof.
2. Description of the Related Art
Semiconductor fabrication is one of the fastest growing industry in the world. Following the rapid progress of electronic technologies, more personalized and functionally powerful electronic products continue to appear in the market.
In the front-end of semiconductor process, at least five photomasks are required to pattern out the active regions, the gate structures, the metallic layers, the source/drain contacts, the metallic interconnects and the bonding pad openings. To form a photosensitive device, an additional masking step for patterning out an illumination area is required after an ion implantation for forming the source/drain terminals. Light energy received from the photo diode array onto the illumination area is converted into an electrical signal so that some image data can be extracted. The most common photosensitive devices include the charge-couple devices (CCD) and complementary metal-oxide-semiconductor (CMOS) devices.
FIG. 1 is a schematic cross-sectional view showing the structure of a conventional photosensitive device. In the back-end of semiconductor process, modular semiconductor devices 100 (or chip) such as the photosensitive device are singulated and packaged on a substrate such as a lead frame or other types of carrier 110. Thereafter, the package is electrically connected with an external printed circuit board 120 or other external printed circuits such as a flexible printed circuit to form a photosensitive module or an image-sensing module. In addition, the larger the area of the patterned illumination area and the greater the number of photo diode array (not shown) within the illumination area, the higher will be the resolution of the photosensitive module.
It is to be noted that a lens 130 is incorporated into the photosensitive module to increase light intensity after packaging the photosensitive device. Moreover, an infrared cutting film 140 is also set between the lens and the photosensitive module for blocking out most non-visible light. The lens 130 and the infrared cutting film 140 are stationed using a holder 150. Hence, the assembled photosensitive device is quite bulky. Furthermore, during the back-end modularization process, micro-particles produced by cutting or contaminant particles emitted from packaging material may lower the yield of the photosensitive module. In addition, the lens 130 and the infrared cutting film 140 are not packaged together in a single back-end process. Thus, efficiency of the packaging process is also compromised.